1. Field of the Invention
This invention relates generally to footwear, and more specifically to a shoe having an indicator responsive to the activity of the person wearing the shoe.
2. Description of Related Art
U.S. Pat. No. 5,500,635 to Mott discloses a shoe having a sole in which a piezoelectric impact sensor, which may comprise polyvinylidene fluoride, is electrically connected to a circuit that contains a battery pack molded into a heel of a sole-and-heel structure. The circuit energizes a light emitting diode (LED). The LED is visible from the rear of the shoe or from some point along the circumference of the sole. In a second embodiment, a shoe is provided with numerous LEDs, one or more impact sensors, and a circuit to process information to turn on the light emitting devices so as to display a bar graph. The LEDs are positioned to be visible to the wearer while walking or running, but may be positioned at remote locations of the sole, heel, or upper of the shoe. The circuit in the second embodiment can process signals from the piezoelectronic impact sensor to light various LEDs to indicate the magnitude of impacts suffered by the shoe. By energizing from one to five LEDs, a bar graph display of impact pressure can be seen on the toe portion of the upper of the shoe. The LEDs can be different colors, or an LCD display may be substituted. Optical fiber bundles may be used to create a variety of multi-colored effects.
U.S. Pat. No. 5,611,621 to Chen discloses electroluminescent (EL) light strips sewn or glued to the side of a sports shoe. The EL light strips can be put together for a rainbow effect.
U.S. Pat. No. 5,452,269 to Cherdak discloses an athletic shoe having a timing system, an activation switch, a messaging display, and a battery. The timing device circuitry measures a time period in which the shoe is off the ground and in the air, and may include custom logic circuits to achieve timer and timing operation. The activation switch in the sole of the shoe may be a simple contact or pressure switch. The messaging display displays a time-based message, but can display other information, such as speed, distance traveled, activity time or duration, foot pressure, or cadence. The display may be a liquid crystal display (LCD) or a LED display that shows alphabetic, numeric, or graphic characters.